Like the title says i have a weird noise that happens between 1100 and 1400 rpms, but is mostly heard louder at 1300. It sounds like a vacuum/whistle, and mostly occurs while under very light throttle to deceleration or coasting. I also noticed it's a little more pronounced when it's colder outside and also when the engine is cold.

I was just driving around trying to trouble shoot this and it sounds from the engine, it's not my throttle spacer that's a different whistle, i think anyways. To me it sounds like a vacuum leak or something but no engine lights or nothing. Everything still runs smooth also.

Another thing is i couldn't reproduce the sound while in Tow/Haul, but mostly because it was hard to achieve rpms below 1500, but i did at one point and didn't hear nothing. Not sure if it's related to anything or MDS but it was part of my trouble shooting. I'm pretty sure i didn't hear this noise before, i could be wrong but i think it's new. Like i said sounds like a vacuum, whistle or a diff whining, but it's coming from the engine bay for sure.

Does anyone have a clue what it could be, or can anyone tell me if they hear this on their trucks. I tried to take a video but it's hard to hear the sound. Thanks for any input.

 

Will it make the noise when your parked and you rev it up or only when your driving?

 

Actually i didn't think of trying that. Good idea, i will try it tomorrow and post back.

 

Nope can't seem to reproduce the sound at when the truck is idling and revving.

 

Hmmm
it almost sounds like the air when your driving its hitting something and making the noise and that's why you can only here it at low rpm and coasting cus road noise drowns it out
Do you notice this noise get better or worse at a certain speeds or it just rpm based ?

 

Mine does this, has since new but you could not really hear it with the factory intake although it is still there. I thought it was the stock intake tube not being smooth since I have an early 09 and bought an Airaid that used the stock tube. But even after getting a new intake, the AFE has a smooth intake tube, is an open design and you can still hear this at part throttle so it is not the tube. Louder in cold weather. I was thinking of getting a Volant since it is a closed intake, would sound great at WOT but seems like a waste of $$ and just put the stock one back on.

 

Well that's interesting, i have an Airaid as well, today the noise didn't seem as bad but it would make sense if that would be causing it. I don't think it's anything that i should worry about was just more curious, as long as im not the only one hearing things hehehe. Kinda sounds like a supercharger, almost, just not that loud.